TB removal and then some!!!

[HAWAIIZR-1]

Originally Posted by A26B

Hi Craig,
I have no personal experience with the Fluidyne radiator and have never read anything negative about it.

I think for the majority of ZR-1 drivers doing street duty, it would be better than the Ron Davis radiator. The Ron Davis unit is an excellent radiator, designed and built for racing at high speed. Bear in mind, the ZR-1 radiator is 3rd in line for cool air, behind the AC condenser & Oil Cooler, which have the potential to heat up the incoming air, but always impede the air flow to the radiator. Add to the restriction in front of the radiator, 5 cores of a Ron Davis & you have significant air flow restriction.

As mentioned above, the Ron Davis radiator is made for racing.... no AC condenser or oil cooler in front, so all that high speed incoming air gets used through the 5 cores.

As a matter of economics, if you have the OE radiator, it's clean,in good condition and you are having overheating problems, try 1 hole in the thermostat, or 2 at the most & see how it works for you. A little sweat equity but no real cost.

Hi Jerry,

Thanks for the feedback and reply. I have been on the move since I acquired 95 #228 so I have not had a chance to service and check cooling system, but got the Fluidyne for trade of couple wheels so I might as well install it. I bought the silicone hoses and clamps from you last year and I have a couple OEM thermostats laying around. The challenge is finding the green coolant for our cars around here. I think a fellow Z owner damaged his LT5 from Toyota red coolant. I remember you sent me the diagram photo of where to drill the holes should I decide to do so. Thanks again for the sound advice as usual. Well, gotta go and install the RaceDeck flooring I bought from Mom!

Craig

[DRM500RUBYZR-1]

Originally Posted by Roadster

Had a new development occur today as I was headed to the WAZOO New Years luncheon. Got an early start and everything was going well......until I looked at the coolant temp on the highway.....I noticed the temp was at 159-160* @70mph and above....just hovering there....so I loop around to go back home.....not wanting to chance the over 2 hour drive each way with what may be a sticking thermostat.
Although the outside temp here is 19-21* and I did the TB coolant bypass months ago....I don't think that it have a 40* swing effect on the temp.....
Now getting off the highway and back on local roads......the temp now goes up to operating range.....200* or higher when stopped for a light....but then still drops to 196* and lower to about 187* when moving....and through all of this the engine is running fine.....and the idle remains to be perfect with each stop..
Got back home fine.....now to figure out the problem......

Tom,
I am not certain that anything is really wrong.
On 50 degree mornings, my car runs in the 170's from home almost to the shore, over 50 miles. Upper 70's when stopped; lower, almost 169 when doing 75.
No holes drilled, and a 180 stat.

The past few days have been in the teens and 20's. Flying along in those temps could keep you down where you experienced.

Don't go crazy yet.
Wait and see how it is when it is at least 50-60 outside.

We have been working on a 71 LT-1.
Left it idling for half an hour; 130 degrees.
Changed the stat from 160- 180 as we had no idea how old the one in there was.
It has come up to 150, but no higher, all with a verified gauge.

Some cooling systems simply are very efficient.

Merry Christmas and Happy New Year to you and your wife!
Stop down sometime!!!
Marty

[Roadster]

Originally Posted by secondchance

Tom,

About 4 years ago I installed a thermo stat with 3 1/8" holes drilled on the flange. It worked fine during the summer months resulting in about 10 degree drop. As soon as we hit cold weather, at highway speed, she was running at 140. Idling, temp would get up to 190 to 200. I would suspect you have a drilled thermostat also.

Yun,
Having not driven the ZR-1 on the highway in extreme weather like yesterday during previous winters.....I don't recall the temps being that low on the highway.....I can't say for sure if or what, if anything was done to the thermostat.....but conditions were just like you described....I was just being concerned....lol.....you think after all the years of driving a big truck....I would remember how drivers would cover the radiator grilles and have only a small opening to limit the air flow to the radiator to keep the temps up during the winter months....I need to go back to Cooling 101....lol and take a refresher course.....

Originally Posted by Dynomite

What deg thermostat do you have? Check Coolant Temp using digital readout #16 fan speed. Do NOT drill holes in thermostats.

It does take a long while to warm up all coolant in radiator. The thermostat can get confused during that initial warm up when radiator coolant is so cold. I do not see a problem.

Happy New Year


Sent from my iPhone using ZR-1 Net Registry

I can't say for sure what deg thermostat I have Cliff.....but I assume it is the stock unit....

I always let the LT5 "warm-up" before driving down the road.....and noticed that in the 19* weather it did take longer than usual before getting up to operating temps.....
There was not anything unusual driving.....but since it is the LT5.....just more concerned.....lol as I want it to run perfect all of the time....
Feeling better that it seems this is normal operation in extreme temps....

Happy New Year to you also......

Originally Posted by XfireZ51

I installed a Fluidyne several years ago trying to address overhating innsummer w AC on. We put in a 180d thermo w 4 holes. It did as u described. Temps dropped to 150 or so when cruising in 30d ambient. Finally, settled on 2 1/8” holes using 180d thermo. Works perfectly in warm or cold. Hot weather driving,
temps are easily kept within the 187- 198d range. Fans come on at 190 and 192.
Cruising temps are below that. My cal for fans is set so temps are always in
Closed Loop Learn range.

I have Marc's chip.....so the fans come on @205* and turn off @200* as mentioned....but in previous years during the extreme cold weather...... I would just start the Z and back it out of the garage and let it "warm-up" for 20 minutes or so and then drive it around the block a few times to get everything lubricated.....

With everything being said.....I would imagine that my cooling system is operating at peak efficiency.....based on all of the replies posted.....

[Roadster]

Originally Posted by DRM500RUBYZR-1

Tom,
I am not certain that anything is really wrong.
On 50 degree mornings, my car runs in the 170's from home almost to the shore, over 50 miles. Upper 70's when stopped; lower, almost 169 when doing 75.
No holes drilled, and a 180 stat.

The past few days have been in the teens and 20's. Flying along in those temps could keep you down where you experienced.

Don't go crazy yet.
Wait and see how it is when it is at least 50-60 outside.

We have been working on a 71 LT-1.
Left it idling for half an hour; 130 degrees.
Changed the stat from 160- 180 as we had no idea how old the one in there was.
It has come up to 150, but no higher, all with a verified gauge.

Some cooling systems simply are very efficient.

Merry Christmas and Happy New Year to you and your wife!
Stop down sometime!!!
Marty

Thanks for the reply Marty......is seems like everyone is in agreement that there is nothing wrong with my cooling system.....which is a good thing.....lol
And the fact that your runs similar to mine as you described and without a drilled thermostat......

And yes quite cold in our area and for most of this week.....

Interesting about the LT-1......I guess we can come to the conclusion that extreme cold temps plays havoc on the cooling temps....


And thanks.....Merry Christmas & Happy New Year to you and your family also......
I will stop down soon.....will give you a call and we'll set up a time....

[XfireZ51]

Sorry Marty, but there’s no way GM would allow the car to run at anything below the point where the ECM is not LEARNING and modifying the fueling for BLMs. No matter what the conditions. That’s part of what cold weather testing is all about.
The coolant needs to be at >80C for that. Anything below that for other than warmup is not what the calibration is looking for. That doesn’t mean it won’t run but it defeats the whole point of Closed Loop operation.

[DRM500RUBYZR-1]

Originally Posted by XfireZ51

Sorry Marty, but there’s no way GM would allow the car to run at anything below the point where the ECM is not LEARNING and modifying the fueling for BLMs. No matter what the conditions. That’s part of what cold weather testing is all about.
The coolant needs to be at >80C for that. Anything below that for other than warmup is not what the calibration is looking for. That doesn’t mean it won’t run but it defeats the whole point of Closed Loop operation.

Well I guess I should expect a recall notice then.

The car feels MUCH stronger at 170 degrees.

I am no engineer, but it has behaved that way for 20 years, and I am good with it.

I won't tell GM, so let's keep it a secret.

Marty

[XfireZ51]

Originally Posted by DRM500RUBYZR-1

Well I guess I should expect a recall notice then.

The car feels MUCH stronger at 170 degrees.

I am no engineer, but it has behaved that way for 20 years, and I am good with it.

I won't tell GM, so let's keep it a secret.

Marty

Most of that were “tricks” to fool the ECM. The issue involves emissions, mpg et al. Not a question of performance which really deals w Open Loop. I’m just stating fact on how the calibration works not making a judgement call.

[Dynomite]

I am with Marty and I have LT5 secrets I explore in public for sanity checks and I welcome ALL Comments
I have been called an Engineer....sometimes......


Sent from my iPhone using ZR-1 Net Registry

[XfireZ51]

Originally Posted by Dynomite

I am with Marty and I have LT5 secrets I explore in public for sanity checks and I welcome ALL Comments
I have been called an Engineer....sometimes......


Sent from my iPhone using ZR-1 Net Registry

Cliff,

I got a few secrets of my own.

[Roadster]

Minor update today......42* out.......took the 94 out for a countryside run.....some nice back roads.....no actual highway driving today.....felt real good.....temps were operating as they normally do......everything went fine...
so as many have mentioned above.....apparently there is nothing wrong with my cooling system...and the results I experienced that day were due to the extreme frigid temps and the highway driving speeds on the highway.......contributing to the cooling temps I saw......